Lighting systems traditionally used in wide area applications such as storage warehouses or manufacturing floors are wasteful in their distribution of light because much of their illumination falls on the tops of pallet racks, palletized goods or manufacturing equipment. Common lighting systems of this type include a variety of high intensity discharge lamps such as metal halide, mercury vapor, lead-gallium, high pressure sodium, etcetera. Another common solution for lighting such an area is florescent lamps. These standard methods of general illumination of wide areas are limiting as their light output is wasteful by not being very well controlled and therefore the conventional remedy for inadequate lighting in areas covered by this sort of blanket lighting solution is to add additional light fixtures and therefore increase cost in capital, maintenance and energy usage.
If the area for illumination is a generally flat area, such as an athletic field, dance floor or open stage, the blanket method of distribution of light from these type of lamps may be adequate in generally illuminating the area, but in a warehouse or manufacturing floor type situation, general illumination from a distributed pattern of high intensity lights creates shadows, outlines and dim areas due to the large amounts of the lamp's output falling on the tops of storage racks, stored product and/or manufacturing machines.
High intensity discharge lamps have many drawbacks in a warehouse and manufacturing area application. Typically a warehouse or manufacturing structure is built with a pattern of equidistantly spaced lamps to illuminate a flat floor area to a certain brightness. It is uncommon to consider equipment or storage rack layout prior to installation of a standard grid of lights. Even if such considerations are made initially, the lighting scheme becomes impractical once the warehouse or manufacturing floor layout is changed. Changing the location of high intensity discharge lamps is difficult as the fixtures are heavy and require the replacement of metal conduit for their high voltage AC power supplies, and the lamps require connection to a suitable roof truss or robust support element due to the weight of the fixtures.
Due to the nature of high intensity discharge lamps it is extremely difficult to direct the light output in a manner precise enough for the purposes of creating defined illumination areas for warehouse or manufacturing operations. The complexity of the optics, heat issues and the uncontrollability of vast quantities of light makes the concept of customizable light pattern outputs unrealistic.
Florescent lamps overcome some of the problems experienced with high intensity discharge lamps as they have somewhat less complicated and demanding fixtures and can be reconfigured to new warehouse or manufacturing floor lay-outs with less effort. Due to the necessity of forklifts and other equipment in such areas, florescent light fixtures still have to be located above the uppermost levels of most storage racks or manufacturing equipment and due to the wide radiant light output pattern of florescent lights a substantial amount of the light is left illuminating the tops of storage racks or the upper surfaces of manufacturing equipment which results in a great deal of wasted or misspent light. Even in the best of florescent light strategies, where the lighting fixture is located directly above an aisle, a great deal of light is still directed at the tops of pallet racks, product on the racks or the tops of manufacturing equipment, the second most illuminated area is the unobstructed floor and the lowest percentage of light is left to dimly illuminate the product labels on the sides of palletized products or the warehouse addresses on the pallet racks where the light is most needed.
Therefore what is needed is an efficient lighting fixture that is sufficiently light of weight and easy to relocate to allow for ease of reconfiguration of the lighting fixture, that includes an easily reconfigurable means of directing portions of the light it produces into designated patterns that can be configured to conform to the areas of desired illumination within a warehouse or onto the manufacturing floor or similar area.